1. Field
Embodiments of the present invention relate to a display device for improving distortion in 3D stereoscopic images, and to a driving method thereof.
2. Description of the Related Art
In general, a display device includes a plurality of pixels provided in an area defined by a black matrix or a pixel defining layer. The display device is categorized into a liquid crystal display (LCD), an organic light emitting display (or an organic light emitting diode (OLED) display), a plasma display panel (PDP), and the like depending on the type of the display substrate.
As examples for methods of driving the display device, there are a sequential driving method receiving data signals in response to scan signals sequentially applied to a plurality of pixels and emitting lights from the pixels in order of data signal arrival, and a simultaneous emission with active voltage method receiving the data signals for one frame and emitting light from all the pixels simultaneously. A frame period of the display device driven in the simultaneous emission with active voltage method includes a non-emission period where the data is written and an emission period where the pixels emit light in accordance with the written data.
Meanwhile, there has been a growing demand and interest for 3D stereoscopic images. In general, the 3D stereoscopic images are based on a stereo vision principle of two eyes. A parallax between two eyes, namely binocular parallax caused by two eyes spaced about 65 mm apart, is a primary factor in human perception of stereoscopic vision, and in a case where left and right eyes are presented with corresponding echo-planar images respectively, a brain can combine two different images, thereby discerning a difference in depth and perceiving a strong sense of presence from the 3D stereoscopic images.
As methods of displaying the 3D stereoscopic images, there are a passive method and an active method. The passive method provides two separate images for the left and right eyes by using a polarizing filter. Another approach for the passive method is to view through glasses with red and blue lenses for respective eyes.
The active method uses shutter glasses separating the left and right eyes, such that images for the right eye and images for the left eye can be separated by blocking each of the left and right eyes in alternating sequence. In other words, temporarily split images are repeated periodically, and the glasses installed with an electronic shutter synchronized to the period are used for viewing. Therefore the method is also called a time split type or a shutter glass type.
In a case where the active method is used for viewing the 3D stereoscopic images, when a left shutter of the shutter glasses is open, only the image for the left eye should be presented, however, problems with this method arise because the image for the right eye is partly shown on the screen. Such interference from other image data on the original image data displayed on the screen is called crosstalk. Further, the temporal differences between the images for the left and right eyes can cause headache or fatigue, and this effect is called flicker.
In a case where the display is driven by the simultaneous emission with active voltage method, a frame includes the emission period and the non-emission period, such that crosstalk phenomenon can be offset in part. However, the problem of flicker caused by the temporal differences between the images for the left and right eyes still remains.